The invention resides in a filter apparatus through which for example the water of a pool is circulated for the removal of impurities. Of course, the filter apparatus may also be used for cleaning other liquids.
Water pools in the form of for example swimming pools or fountain pools as present for example in shopping malls or gated communities or parks or even in front yards of residences require cleaning of the water by filters in order to prevent the water from fouling up.
Such a pool filter comprises for example a housing in which a filter cartridge or another filter structure is arranged for filtering the water of a pool. The pool water is circulated through the filter housing via an inlet pipe and leaves the filter housing through an outlet pipe arranged so that the water is conducted in the filter housing through the filter structure. The filter structure needs to be cleaned or replaced from time to time to prevent clogging thereof. For cleaning the filter structure, the housing generally needs to be opened to remove the filter structure for the cleaning or replacement.
U.S. Pat. No. 7,794,591 discloses for example a pool filter with a housing defining a fluid chamber and including four filter cartridges. The pool water is pumped from the pool into the housing and radially through the filter cartridges and flows axially out of the filter cartridges into a discharge pipe via which the cleaned water is returned to the pool. Impurities are deposited on the outer surfaces of the filter cartridges. From time to time, the housing needs to be opened for the replacement of the filter cartridges.
It is the object of the present invention to provide a filter with a filter structure disposed in a housing wherein impurities are uniformly deposited on the filter surfaces for long filtering periods and effective cleaning operation and the filter structure does not need to be removed for cleaning but filter cleaning is performed automatically in a simple and very effective manner while the filter structure remains installed in the housing.